Gary Johnson is prepared for a fair share of thin-lipped smiles, perfunctory handshakes and frosty receptions from fellow Championship managers this season. "We're going to be the poor relations but we'll be seen as a danger – managers will be under pressure when they play us," he says. "They won't want to lose to Yeovil."

Only 10 years after entering the Football League, the Somerset team assembled on a shoestring will play the first Championship game in their history when they visit Millwall on Saturday.

"My players earn around four times less than the average Championship first-teamer," says Johnson. "And there are quite a few players at Queens Park Rangers who will be earning more in a week than my entire squad combined, but I believe we can compete and enjoy it. There are a lot of big names in the Championship and it's a huge challenge but I want us to see every game as a celebration of our achievement in getting here."

Victory over Brentford in the League One play-off final catapulted Yeovil into a division many associated with the club had never considered feasible for them. "I've had to brainwash a few people," jokes Johnson. "There was a feeling that League One was maybe Yeovil's limit but my job has been to convince them it wasn't, to get them to believe. I've had to try and change the mindset."

Now Johnson's sole remaining interest in League One is Oldham Athletic where his 32-year-old son, Lee, is in charge. At almost 58, Yeovil's manager has enjoyed an eclectic, frequently successful career in the dug-out. It really took off when, as John Beck's assistant during the early 1990s, he helped sweep Cambridge United up the divisions and to within touching distance of the Premier League. "We lost the 1992 play-off semi-final to Leicester," recalls Johnson. "We got that close.

"I learned a great deal from John. There were lots of things he did I learned not to do and there were things that I'd never have done myself, but we had some fantastic times. In many ways John was ahead of his time. He was using statistics and sports science when other managers weren't even thinking about them.

"At the start we were just two young coaches trying to make a living. We signed players who had been seen as promising youngsters at bigger clubs but hadn't quite turned out as well as originally hoped. John convinced them they could fulfil their potential if they bought into his philosophy and we built a team full of very good individuals, people like Dion Dublin and Liam Daish.

"Cambridge taught me that your signings must really want to buy into your ideas, buy into the way you want to play. You have to sign people to fit your team, not the other way round.

"It's why we do a lot of due diligence on every player who comes to Yeovil. Everything at this club is about value for money, it's about finding the next Wayne Rooney before he is Wayne Rooney. This summer we've signed Kieffer Moore [the former Dorchester Town striker] who was the best player in non-league football last year – or so he tells me!"

Johnson's apprenticeship at the Abbey Stadium served him well during not only an exciting interlude coaching Latvia but an earlier stint at Yeovil and a spell at Bristol City during which, five years ago, they lost a Championship play-off final to Hull.

Today Bristol City are in League One. "Bristol is, I think, the fifth biggest city in England so it could do with a Premier League club. Just missing out in 2008 was very disappointing," says Johnson. "But nothing's certain in football and now Yeovil are the best in the west and in the same division as Leeds and Nottingham Forest."

He trusts that once illustrious pair will be startled by a Glovers ensemble reflecting his excellent contacts. Michael Ngoo, a 6ft 6in forward, has been loaned from Liverpool, Billy Clifford, a central midfielder, has been borrowed from Chelsea and another loan deal, that of the centre-half Alan Tate from Swansea, was confirmed through an impressively imaginative PR stunt.

Inspired by the formal declaration of last week's royal birth at Buckingham Palace, a similar easel supporting an official-looking A4 sheet was positioned outside Huish Park. "Yeovil Town was safely delivered of a loan defender at 1pm when Alan Tate from Swansea City joined until 2 January 2014," it declared.

"We try to keep Yeovil in the news and it was a quality idea from a member of our media department," says Johnson. "He was woken by a storm in the middle of the night and suddenly thought of it. It's made everyone smile."

Such bonhomie is all very well but his mission now is to leave fellow Championship managers frowning. "We think we've got a strong squad," says Johnson. "But we've got to prove it."